deps!: update multiformats to v13

[achingbrain]

v13 of multiformats was release which is a port to TypeScript.

There are no API changes so the upgrade should be relatively painless but it's been released as a major for safety.

BREAKING CHANGE: multiformats have been upgraded to v13 - the API should remain identical

Definition of Done

Before submitting this PR, please make sure:

• [x] The work addresses the description and outcomes in the issue
• [ ] I have added relevant tests for new or updated functionality
• [ ] My code follows conventions, is well commented, and easy to understand
• [ ] My code builds and tests pass without any errors or warnings
• [x] I have tagged the relevant reviewers
• [ ] I have updated the READMEs of affected packages
• [ ] I have made corresponding changes to the documentation
• [ ] The changes have been communicated to interested parties

References:

Please list relevant documentation (e.g. tech specs, articles, related work etc.) relevant to this change, and note if the documentation has been updated.

• multiformats@13.x.x - https://github.com/multiformats/js-multiformats/releases/tag/v13.0.0

[achingbrain]

Tagging @ukstv for review

[ukstv]

LGTM. Going to cut a major version bump after the merge.

[ukstv]

@achingbrain Released as v5